That was the dubious conclusion of a Demos report launched last night at the British Academy. The Power Gap, the first research output of James Purnell's Open Left project, effectively maps the distribution of everyday power in Britain. "Power" here is conceptualised as "power to" (capability) rather than "power over" (domination), and informed by Purnell's adaptation of Amartya Sen's "capabilities" approach to invigorate the left, after the age of Giddens and Blair.

On one hand, the Power Gap report exemplifies all that's best about Demos's work: it's a highly accessible analytic tool to slice through the political bluster around the imperatives for decentralisation and civic empowerment – especially as it appears in David Cameron's vision of a "big society".

But on the other hand the report is symptomatic of the shortcomings of thinktank research, driven as it by political alignment. Consider the glaring contradiction of this report. It was grandly announced as a counterpoint to measures of elite power that painted a granular picture of power from the grassroots up.

Yet the indicators for everyday power weren't chosen by consulting citizens, either individually or collectively. Instead, they were selected internally by the Demos team. As a consequence, the power index is computed using indicators which, at the very best, are a little arbitrary and, at the very worst, are slightly self-serving.

The report divides everyday power into three aspects: personal control, resilience and social agency. The first is relatively uncontroversial, given that it uses income, education, and occupation as proxies for personal control. But the second – resilience – seems to be given undue importance. So the weighting of indicators is an issue here.

It is the third, though, that is most problematic. Social agency is also the aspect of Sen's capabilities approach which is the least developed, and yet it is the most central plank in New Left's remodelling of the citizen-state equation. Bizarrely, the report uses voter turnout and seat marginality as proxies here. If you're an advocate of electoral reform (as Purnell is) it's easy to see why you would believe it should feature strongly. But how many everyday people consider seat marginality a significant aspect of social agency?

The report's instrumentality to Purnell's Open Left programme is most startlingly naked when you consider the finding that there is an inverse correlation between the report's calculation of powerlessness and people's perception of their own power. In other words, citizens living in areas highlighted as being most disempowered disagree; they believe themselves to be very powerful. Purnell's response is that this is indicative of "adaptive preference": people have simply learned to assimilate their disempowerment and internally rework it to exercise control over their personal lives. But this is patronising in the extreme, redolent of Marxist false consciousness arguments, and isn't helped by his example of Indian women internalising subjugation as an illustrative point.

Surely a more compelling explanation would be that the inverse correlation exists because people calculate their everyday power otherwise where voter turnout and seat marginality don't jointly account for a third of their score, but where social networks and influence do? Factoring in the variables of kinship circles, organisational life and friendship groups would certainly paint a richer picture of everyday social agency. We should applaud Purnell and Demos for making such a timely intervention, but much work is needed to make our understanding of power both more rigorous and responsive to how power is exercised and how it emerges, socially.